Each year numerous automobile accidents are caused by vehicle driver distractions. The National Highway Traffic Safety Administration (NHTSA) estimates that driver distraction is directly involved in twenty to thirty percent of all automobile accidents or roughly 1.6 million automobile accidents in the U.S. annually. Visual distraction of the driver is attributed to many of the accidents. For this reason, Delphi Automotive Inc. of Troy, Mich. has developed and demonstrated a real-time vision-based system that measures driver distraction based on eye gaze direction (on-road vs. off-road), and issues an alert if the proportion of off-road eye gaze over a specified period of time exceeds a threshold. See, for example, the proceedings of the 2006 International Consumer Electronics Show (CES) in Las Vegas, Nev., Jan. 4-8, 2006, and the aforementioned U.S. patent application Ser. No. 11/130,360.
Driver distraction alerts may take different forms and are primarily designed to provide visual, auditory or tactile feedback to stimulate re-orientation of the driver's attention to the forward road. When properly calibrated, this kind of system can beneficially train a driver to reduce the frequency and duration of off-road glances. However, it must be recognized that some off-road glances are normal and even desirable, and that driver alerts can themselves be a source of momentary distraction to an attentive driver. Accordingly, what is needed is a method of mitigating driver distraction that does not adversely affect the response time of an attentive driver.